The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Shift mechanisms for motor vehicle transmissions take many forms. In a typical manual transmission, a plurality of parallel shift rails are acted upon by an operator guided shift lever and include shift forks which engage and translate synchronizers and clutches which achieve a desired gear. In automatic transmissions, hydraulically operated clutches and brakes controlled by a plurality of logic and control valves engage, disengage and brake elements of planetary gear assemblies. In a newer transmission type, the dual clutch transmission (DCT), a plurality of synchronizer clutches on two countershafts are translated into and out of engagement by associated actuators.
Such dual clutch transmissions typically have five, six or seven forward gears or speeds and reverse. In a typical dual clutch transmission having five forward gears and reverse, at least three actuators, three shift linkages and three double synchronizer clutches will be required. The actuators which will typically be bi-directional, electric or hydraulic devices will generally be the most expensive components of the shift assembly. In a typical six speed, dual clutch transmission, at least four actuators, shift linkages and three double synchronizers clutches and one single synchronizer clutches will be required. Again, the actuation control system will generally be the most expensive component of the shift assembly.
Because of their excellent fuel economy and sporty performance which parallels that of a manual transmission, dual clutch transmissions are gaining recognition and acceptance in the marketplace. Given this trend, activity directed to enhancing all aspects of dual clutch transmission design and operation is ongoing and the present invention is the result of such activity.